Known land vehicles suffer from a variety of problems making them less than perfectly suited for a variety of applications, such as: agricultural work; mining and geological work; exploration or mapping of remote areas; academic research and the like. In particular, known land vehicles suffer from the problems of not having robust drive units capable of: being modular; being configurable in a variety of ways to form a variety of land vehicles; being readily replaceable (for example, for maintenance purposes); having ease of connectivity to a vehicle electric power source; being water-tight and optionally of floating; being readily controllable (for example, remotely); having structure for readily disconnecting an electric drive motor from ground engaging wheels; having ground engaging wheels capable of propelling a vehicle comprising the drive unit on water as well as land, etc. In addition, and in some instances as a result of the foregoing, known land vehicles suffer from the problems of: lack of robust suspension systems (for example, for traversing uneven terrain or large obstacles); carrying instrument payloads, particularly in a well-sealed environment and with ease of installation and removal from the vehicle (or drive unit); being amphibious; being remotely controllable; being skid-steerable (by differential movement of wheels on opposite sides of the vehicle); having a single electrical power source for a plurality of vehicle drive units; being towable, etc.
There remains a need for improved land vehicles and vehicle drive units addressing some or all of the aforementioned problems.